Reaction product of hexachlorocyclopentadiene with thiol compounds and lubricants containing same



United States Patent 2,773,832 REACTION PRODUCT OF I-IEXACHLOROCYCLO- PENTADIENE WITH 'IHIOL COMPOUNDS AND LUBRICANTS CONTAINING SAME Ellis K. Fields, Chicago, Ill., assignor to Standard Oil Company, Chicago, 111., a corporation of Indiana No Drawing. Application November 28, 1952,

' Serial No. 323,141

2 Claims. (Cl.25248.8)

for imparting extreme pressure properties to such oils.

It is a further object to provide a method of preparing novel sulfur and chlorine containing compounds which are useful intermediates in the preparation of various sulfur and chlorine containing organic compounds. Additional objects will be apparent from the following detailed description of the present invention.

Briefly, the present invention relates to novel sulfur containing derivatives of hexachlorocyclopentadiene and to the method whereby'such derivatives may be prepared by reacting that compound with a compound containing at least one active thiol group. In accordance herewith, the term active thiol group shall refer to the reactive group --SM, wherein M may be hydrogen or an alkali metal, e. g. sodium or potassium. The two methylene chloride atoms at the 5-position on hexachlorocyclopentadiene are the most reactive and are replaced first at temperatures of from about 50 F. to about 215 F. The remaining chlorine atoms appear to be attacked at somewhat higher temperatures, e. g. 160 F. to about 300 F. Hexachlorocyclopentadiene should be employed Cir in excess of the stoichiometric amount when reaction of only one chlorine atom is desired and the sulfur compound is preferably added to the hexachlorocyclopentadiene. An alcohol solvent such as methanol is preferably employed during the reaction although benzene or other suitably inert solvent may be used. The reactants are then agitated for from about 1 to 48 hours, usually about 2 to 10 hours, filtered and purified to obtain the derivatives of the present invention.

Hexachlorocyclopentadiene may be readily prepared by reacting an aliphatic hydrocarbon containing at least 5 carbon atoms or an alicyclic hydrocarbon containing 5 carbon atoms in the ring, or the chlorinated derivatives of these compounds, with chlorine at temperatures between about 650 F. and 1025 F. The 5 carbon atom alicyclic hydrocarbons having the five carbon atoms in the ring, and 5 carbon atom aliphatic hydrocarbons wherein the number of carbon atoms in the longest straightchain is 4 or 5 are particularly suitable for the preparation; of hexachlorocyclopentadiene in this manner. Since a detailed description of this method of preparing hexachlorocyclopentadiene is set forth in U. S. 2,509,160 it is considered unnecessaryfherein to- .since many of these compounds arejsubstantially unstable and are ordinarily unavailable as such, it is preferred to employ the alkali metal salt of such unstable thiol derivatives. Thus, for example, xanthic acids, thiocarbonic acids, thiocarbamic acids, thiolic acids, and dithionic acids are compounds of the type which will form derivatives in accordance with the present invention but since these compounds are more or less unstable in the acid form, the alkali salts thereof are preferably employed.

Mercaptans and the alkali metal mercaptides thereof which may be represented empirically by the formula RSM wherein R is a hydrocarbon radical and M may be either hydrogen or an alkali metal, e. g. sodium or potassium, will react with hexachlorocyclopentadiene in accordance with the present invention. As examples of such compounds, are methyl mercaptan, ethyl mercaptan, butyl mercaptan, hexyl mercaptan, dodecyl mercaptan, octadecyl mercaptan, benzyl mercaptan, thiophenol, etc.

In each of the classes of organic compounds referred to empirically herein, the hydrocarbon radicals represented by R or R may be alkyl, arylalkyl, cycloalkyl aryl, and these may be substituted with various reactive groups which do not take part in the reaction with hexachlorocyclopentadiene, e. g. carboxyl, hydroxyl, nitro-, etc.

The alkali metal salts of the various xanthic acids having the formula ROCSSM, wherein R is a hydrocarbon radical preferably containing from 1 to 24 carbon atoms, e. g. ethyl, butyl, isoamyl, lauryl, octadecyl, phenyl, etc,, may likewise be reacted with hexachlorocyclopentadiene in accordance with the present invention.

The alkali metal salts of the thiocarbonic acids containing an active thiol group which have the general formula MZSICOZ/ wherein x is a positive integer from 1 to 3 inclusive and y may be 0, 1 or 2 will react with hexachlorocyclopentadiene in accordance herewith. Examples of this type of compound are the sodium, or

potassium salts of thiocarbonic acid, dithiolcarbonic acid,

and trithiocarbonic acid. In addition, the organic derivatives of such salts, e.'g. sodium or potassium salts of methyl trithiocarbonic acid, hexyl trithiocarbonic acid, lauryl dithiocarbonic acid, etc. will react in accordance herewith. Such compounds have an organic radical, e. g. a hydrocarbon radical, replacing one of the alkali metal atoms.

The alkali metal salts of the thiocarbamic acids having the general formula RR'NCOySxM wherein either or both R and R may be hydrogen or a hydrocarbon radical preferably containing from 1 to 24 carbon atoms, y may be 0 or 1 and x may be 1 or 2, will react with hexachlorocyclopentadiene to form novel compounds in accordance with the present invention. Examples of such compounds are the sodium or potassium salts of thiolcarbamic acid (HzNCOSM), and dithiocarbamic acid (HzNCSSH) and the various hydrocarbon substituted analogs of these salts, e. g. the dibutyl dithiocarbamates, dibenzyl dithiocarbamates, ethylhexyl dithiocarbamate, diethyl thiolcarbamate, lauryl thiolcarbamate, dioctadecyl dithiocarbamate, etc.

Another group of compounds which react with hexachlorocyclopentadiene are the] thiolic acids and their salts having the general formula RCOSM wherein R is a hydrocarbon radical, which may be alkyl, aryl, alkyl aryl, cycloalkyl, preferably containing from 1 to 24 carbon atoms Examples of such compounds are thioacetic acid, thiobutyric acid, thiobenzoic acid, thiolauric acid, thiostearic acid, etc. and alkali metal salts thereof.

In like manner the dithio acids, sometimes referred to as dithionic acids, and their alkali metal salts having the general formula RCSzM will form the novel compositions of the present invention when reacted with hexachlorocyclopentadiene. R is a hydrocarbon :radical preferably containing from 1 to 24 carbon atoms, e. g. methyl, propyl, nonyl, dodecyl, octadecyl, phenyl, cyclohexyl,

etc.

The thiosulfonic acids and their salts may likewise be reacted with hexachlo'rocyclopentadione to prepare novel compositions of matter in accordance with the present invention. These compounds have the general formula A reaction temperature in the range of from about 50 F. to about 300 F., depending upon'the reactants, may be employed. Thus, the methylene chloride atoms react first at temperatures of from about 50 F. to about 250 RSOzSM wherein R is a hydrocarbon radical preferably F. and the remaining chlorine-- atoms are attacked at containing from 1 to 24 carbon atoms. Examples of such somewhat higher'temperatures, e g. about 160 F. to compounds are methyl thiosulfonic acid, octaclecylthioabout 300 F. In general, higher reaction rates areiobsulfonic acid, toluene thiosulfonic acid, etc. I tainable with inc s g E PHQ IQ- It should be understood that the suggestion of various The reaction is preferably effected the presence of specific active thiol group containing compounds herein 10 inert solvents such as certain lower alcohols,; e. g.-;ethanol, is not intended to function expressly'or impliedly for the n l, iQ an methyl Cellosolve, hydroexclusion of others coming within the definitions hereincarbons, etc. However, the present process will proceed above set forth. I v in the absence of inert solvents. I

The reaction of the foregoing active thiol compounds The process may be carried out batch-wise, continu- With hexachlorocyclopentadiene' is preferably conducted ously or semi-continuously. The particular reaction equipwith the alkali metal derivativ e of the sulfur compound h p y forms 110 P of the P e illvelition but the thio-cotnpound itself may be employed as such, and, therefore, need not be set forth in detail. Reactions Those compounds, such as mercaptans, which are suf- 0f the l invention a he carried out in ficiently stable in the .-SH-f m may be r a ted ith tional reaction kettles or autoclaves. hexachlorocyclopentadiene but it is preferred to conduct 111 Table 1 is Set forth information 0!! 60111110111148 P such a reaction in the Presence of a r t su h s pared in accordance with the present invention. This s d um y te SOd l t Y1 f,-.0r the like, thus reinformation, as well as that in the following operating sulting in the reaction of th alkali alt ith h X h1o1- example, is included herein for the purpose of specifically cyclopentadiene illustrating the invention without necessarily limiting the Based upon the number of chlorine atoms it is de- Same The follflwing Operating example corresponds sired to replace the hexachlorocyclopentadiene will or- Example 1 in Table 11 dinarily beco'ntacted with from about 0.003 to about 10 H1016 0f hexachlolocyclopehtadiehe Was added moles of thiol type compound. As indicated, itis neces- Slowly a Solution of the Sodium Salt (5f y' sary to maintain a substantial excess, e. g. from 10% to caplah Comprising mole of the mefcapthll and 111016' 300% of hexachlorocyclopentadiene, when it is desired to 30 of Sodium methylate in 250 of methahol- A Vigofohs replace only one chlorine atom. I exothermic reaction occurred. The mixture was refluxed Without being bound by any theory herei ex ed for about one hour; the resulting product was filtered to o im lied s to the xa t me ha i by hi h h d l' remove sodium chloride and the filtrate was evaporated in compositions are produced, it appears that the reaction Vacuum at giving 103 gl'ams of a y dark of hexachlorocyclopentadiene and an active thiol-containhile liquid which Was soluble in h D i jug ompound, e, a odi mempfide t ithi In the examples set forth in Table 1,no particular effort bd d as f ll w was exerted to obtain optimum yields; accordingly, no

G] Cl C V. 0] reference is made in the table to yields. For the mes:

+2RSM +2M01 part, however, the yields were satisfactory, usually su b- O1 01 C1 C1 40 .giantlally theoretical based upon hexachlorocyclopii'taene. ISR The new products of this invention may be readily re- I I acted with dienophiles such as maleic anhydride," acrolein, C1 01 I G 01 I acrylonitrile, ethyl acrylate, etc., to give further novel U +M2CS3 U +2MO1 compositions, for example: C1 O1 C1 C1 H 0 Cl Cl S\ 1 8 C I O1 til-0 Cl 0 1 g O 01 I /O (oeH s )C 1 wherein R is an organic radical, eg. a hydrocarbon j; radical, and M is an alkali metal. The reaction of hexachloroc'yclopentadiene and other types of active thiol g g fihg g gg containing compounds proceeds in essentially the same bicycle (2.2;1.)' manner heptene 7 2,3 dicarboxyhc anhydride Table Product Ratio of Example Thiol Reactant Type Thlol Calculated Found Reactant '1 i toCsCla Cl, percent (Based on Structure) 8, per- 01, pr- S, pet- I ,cent cent centn-hexyl mereaptan 1.5:1 31.3 (0501480331312). 15.15 31:32 14. 67 n-hexylmercaptau 4:1 14.2(C5Clz(SC sH1a)4) 25.7 14.9 .(I) n-hexylmercaptan 6:1 0 (05(SCsHn a 25.2 0.8 26.5 K ethyl xanthate 2:1 20. 1 (oiomsgooo nm) 36.3 20.6 36. 1

. .3 f hi ttgililtfiiitlfifita 13365? a 333ii iiil fi fi ifififit: 5312 till 55 Na dlbutyl dithiocarbamat 'R R'NCOiS=MJ.; 2:1 28.3 (C5Cl4[SCSN(CiH9)2l5);- 21.0 25;! P1936 *No sulfur analysts obtained.

The anhydride so produced may be readily hydrolyzed to the acid which has excellent rust inhibiting properties when added to mineral oils such as turbine oils, etc.

The di-mercapto product of Example 1 in the table above was tested as an E. P. agent in SAE 30 lubricating oil. 2% of that product in such oil resulted in a lubricant which carried a load of 80 kg. without seizing and which did not weld until a load of 300 kg. was reached when tested in the Shell 4-ball E. P. test machine (Four- Ball Testing Apparatus for Extreme Pressure Lubricants, Boerlage, Engineering 136, 46 (1933)). This compares to a load of only 60 kg. for such oil without the additive. Products of the present invention may be added to lubri cating oil for the purpose of imparting extreme pressure properties thereto, in an amount of from 0.2 to about 20% and preferably from about 0.5 to about 10% As set forth hereinabove, the compounds which may be reacted with hexachlorocyclopentadiene in accordance herewith are those containing an active thiol group, i. e. compounds containing a reactive SM group where M may be hydrogen or an alkali metal. And as enumerated in detail, this active thiol group may be part of a large number of different classes of organic thio-compounds. When such compounds are reacted with hexachlorocyclopentadiene, either hydrogen chloride or an alkali chloride is split out and the remainder or residue of the original thin-compound is, as hereinabove described, attached to a carbon in the ring replacing a chlorine atom. For the sake of brevity and mechanical simplicity, these residues of the original thiol compound which after reaction are Cl Cl RS SR wherein R is an alkyl radical having from 1 to 18 carbon atoms, inclusive.

2. The composition of claim 1 wherein R is a hexyl radical.

References Cited in the file of this patent UNITED STATES PATENTS 2,454,108 Walling Nov. 16, 1943 2,503,290 Norris Apr. 11, 1950 2,697,103 Ordas Dec. 14, 1954 OTHER REFERENCES Davy: The Mechanism of Action of E. P. Lubricants, article in Scientific Lubrication, September 1949, pages 714. 

1. A MINERAL LUBRICATING OIL AND BETWEEN ABOUT 0.2 AND ABOUT 20% BY WEIGHT, BASED ON SAID OIL, OF A COMPOUND HAVING THE FORMULA 